Device for grinding bottoms of circular chasers



March 27, 1934. w. J. HOGG 1,952,206.

DEVICE FOR GRINDING BOTTOMS OF CiRCULAR CHASERS Filed July 24.. 1931 F gg;

Patented Mar. 27, 1934 JNiTED STATES DEVICE FOR GRINDING BOTTOMS OF CIRCULAR CHASEBS William J. Hogg, Cleveland, Ohio, assignor to The National Acme Company, Cleveland, Ohio, a

corporation of Ohio Application as 24, 1931, Serial No. 552,853

3 Claims.

This invention has to do with means which may be designated as a grinding fixture for facilitating the grinding of the bottom of circular chasers of threading dies true with the threads thereof.

In practice, these circular chasers are made substantially as shown and described in my contemporaneously pending application Serial No. 459,700, filed June 7th, 1930, but it is essential that the bottoms of the chasers be ground true with the threads thereof.

The object of the present invention, therefore, is the provision of improved means for so setting the chasers as to permit the grinding of the bottoms thereof true, which means is simple in construction, inexpensive to manufacture, and easily adjustable for chasers of different sizes.

In the drawing accompanying and forming a part of this specification, Fig. 1 is a top view of the present improvement.

Fig. 2 is a side, partly sectional, View thereof, and

Fig. 3 is a detail View illustrating the manner of supporting the chaser supporting buttons or devices.

Similar characters of reference indicate corresponding parts in the several views.

Before explaining in detail the present improvement and mode of operation thereof, I desire to have it understood that the invention is not limited to the details of construction and arrangement of parts which are illustrated in the accompanying drawing since the invention is capable of other embodiments, and that the phraseology which I employ is for the purpose of description and not of limitation.

In the present improvement, the fixture comprises a hardened block 2 provided with a plurality of T-shaped slots 3 in its top face, shown as three in number.

Supported on the top face of this block are a plurality of buttons 4, each having a V-sliaped head 5, that is each head has a single circular tapered or V-shaped edge and these tapered edges are all equi-distantly located from the bottoms of the buttons and these buttons are secured for adjustment in the T-shaped slots by headed bolts and nuts 6, whereby the buttons may be adjusted toward and from the center of the block for the reception of chasers of different diameters. These buttons are circularly arranged and all have their axes equally spaced from the axis of the chaser.

By positioning the chaser 7 so that the thread 55 grooves thereof will properly fit the V-shaped heads of the buttons, the chaser will be properly supported in a true position so as to permit the bottom of the chaser to be ground true with its thread and by adjusting the buttons inwardly or outwardly, various sizes of chasers may be supported to permit this true grinding of the chaser.

As the adjustable buttons have but a single V-shaped rib, it will be apparent that they can be used with a chaser having any desired number of threads, twelve per inch, sixteen per inch, or any other number, whereas if they had more than a single V-shaped rib it would be necessary to provide buttons to correspond with the number of threads on each chaser to be ground.

It is to be understood that, by describing in detail herein any particular form, structure or arrangement, it is not intended to limit the invention beyond the terms of the several claims or the requirements of the prior art.

Having thus explained the nature of my said invention-and described a way of constructing and using the same, although without attempting to set forth all of the forms in which it may be made, or all of the modes of its use, I claim:

1. A chaser grinding fixture adapted particularly for the grinding of circular chasers or cutters for circular dies comprising a stationary supporting block having a plane faced top, a series of adjustably supported circular buttons equally spaced from the axis of the chaser and adjustable for different diameters of chasers, each having a single tapered non-cutting edge adaptedto engage in a circular groove of the chaser having any desired number of threads thereby to hold the chaser at its pitch diameter, all of said buttons located to have the tops of the buttons in the same plane and spaced above the top of the block, each of said buttons having its head of greater circumference than the base of the button thereby to support the chaser spaced from the top of the block and the buttons except at the V-shaped engaging portions thereof thereby to grind the face of the chaser true with the pitch diameter.

2. A chaser grinding fixture adapted particularly for the grinding of circular chasers or cutters for circular dies comprising a stationary supporting block having a plane faced top and a series of radial T-shaped guideways, a series of adjustably supported circular buttons equally spaced from the axis of the chaser and adjustable for different diameters of chasers, each having a single tapered non-cutting edge adapted to engage in a circular groove of the chaser having any desired number of threads thereby to hold the chaser at its pitch diameter, all of said buttons located to have the tops of the buttons in the same plane and spaced abowe the top of the block, each of said buttons having its head of greater circumference than the base of the button thereby to support the chaser spaced from the top of the block and the buttons except at V-shaped engaging portions thereof thereby to grind the face of the chaser true with the pitch diameter, each of said buttons having a shank terminating in an enlarged T-shap'ed end located in a radial guideway.

3. A chaser grinding fixture adapted particularly for the grinding of circular chasers or cutters for circular dies comprising a stationary supporting block having a plane faced top and a series of adjustably supported circular buttons equally spaced from the axis of the chaser and adjustable for difierent diameters of chasers each having a single tapered noncutting edge adapted to engage in a circular groove of the chaser having any desired number of threads thereby to hold the chaser at its pitch diameter, all of said buttons located to have the tops of the buttons in the same plane and spaced above the top of the block, each of said buttons having its head of greater circumference than the base of the button thereby to support the chaser spaced from the top of the block and the buttons except at the V-shaped engaging portions thereof thereby to grind the face of the chaser true with the pitch diameter, and means projecting through the buttons for adjustably clamping the buttons to the block.

WILLIAM J. HOGG. 

